I know that "ɪ" as in "it[ɪt]" is a relaxed sound with lips, tongue, teeth all relaxed, so it sounds between "i"and "e". while "i" as in "eat[i:t]" is a tensed sound.
But sometimes when I hear native speakers pronounce some "ɪ"s, there doesn't seem to be any difference between the two. So does it all depend on individual difference or something?

